InGaAs vs. Ge IR Detectors
Both Indium Gallium Arsenide (InGaAs) and Germanium (Ge) photodiode detectors are commonly used to measure optical power in the near IR (NIR) range. Newport offers various versions of NIST traceable InGaAs and Ge detectors (see Low-Power Calibrated Photodiode Sensors 918D series and Low-Power Calibrated Photodiode Sensors 818 Series). The specifications of these detectors are very similar, except for only a few key areas: shunt resistance and die capacitance, for example. However, these differences make a huge performance difference and hence the price difference.